Switch-key.



N0- 828,089. PATENTED AUG; '7, 1906.

- E. B. CRAFT.

SWITCH KEY.

APPLICATION FILED JULY5,1904.

4 SHEBTS+SHEET 1.

Zita 622 Z02;

I Edaard Z51 fia z, I

W 9 1 rywmw PATENTED AUG. 7, 1906.

E. 3.0mm. SWITCH KEY. APPLIGATIQN FILED JUL-Y5, 1904.

4 SHEBTSSHEET Z.

PATENTED AUG. '7, 1906.

r E. B. CRAFT.

SWITCH KEY. APPLIQATION FILED JULY5,1904.

4 $HBETSSHBET 3.

[7206225021- ZaZa/Qiiai 6 w .UNITEE srnrns imam te e EDWARD B. cnnrr, orcmciie'o, ILLINOIS, AssicNoR To WESTERN ELECTRIC ILLINOIS.

COMPANY, OF CHICAGO, ILLINOIS, ACGRPORATION OF SWITCH KEY.

ssaose.

150 all 'u'zhum may concern.- v

it known that I, EDWARD 'B. CRAFT, a citizen of the'Uinted States,'1es1d1ng at Chlcago, in the county of Cook and State of Iili-' nois, have invented eertainnew and useful Improvement in Sw1tchKeys, of which the following is a full, clear,- concise, and exact desc non. I

nvention relates to a switch-key for one-exchanges, and has for its object tide an improved device which will be ,naily adapted for use as -a party-line ringing-key and which will be convenient,

rniiable, and certain in i-ts operation, compact and durable in construction, and so ar r that actuation of the device at improper times will be prevented. i

i'vi y invention contemplates a switching device which will lie-adapted to be mounted upon. the-horizontal key-shelf of a telephoneswitchboard in association with the operatcrs cord-circuit and employed forfeit'her code or selective signaling to apply current of distinctive character to the line to operate the bells of substations thereof. The key 'may comprise number of actuating-shafts mounted vertically to rock in bearings in a suitable framework, each shaft being adaptwhen operated to actuate individual switeh-springs,and so to apply a particular current to a party-line. Whenever anyone of the shafts is rocked to operate itsassociated switch-springsya blocking device is the preferred form of my invention I employ a series of such vertical shafts, each s.

having two sets of switclnsprings associated therewith, one set on either side thereof Each shaft has a double-crank lever above the supportmg-frame whereby the shaft maybe rocked in either direction to operate its asseciated springs, The key may eons prise iiave actnating-shafts and their E380 ciated switchsprings and may becenvensp: ifi'cation of Letters Patent.

Application filed July 5,1904. Serial no. 215.209.

applied to iaft . Patented Aug. 7, 1906.

iently employed to signal subscribers of a .ten party line. Two latch-bars are pro vided, one on either side of-the row of shafts,

adapted to be actuated by each shaft, according to the, direction in which the shaft is rocked. Either bar when actuated is adapted to lock the actuated shaft in itsop/ erated position and to engage the remaining shafts atedshaft is returned to its normal position. The latch-bar when so moved is arranged to be held by the armature of. an electromag-- be arranged proper distin'ctive signalhas been afipli'ed to the line,

net. The electromagnet may to be energized as soon as=the whereupon its armature wi release thelatchv bar and the apparatus will be restored to its normal position. With the in such a manner as to prevent. sub-: sequent. manipulation thereof until the actu- 6 5- automatically unactuated shafts locked during the opera tion of a given shaft confusion in the applicationof signals to a'partysline is avoided, since the operator cannot while a distinctive signal is being applied to a party-line to signal one of the subscribers thereof impose a current of different characteristics upon the circuit to signal another substation of the line.

to the accompanying drawings, wherein- I Figure 1 is a view in side elevation of a party-lineringing-key embodying my invention. Fig. 2 is a plan view thereof. 3

is a sectional; plan view on line 3 3 of Fig. 1.

Fig. 4 is a sectional plan view on line 4 4 of Fig. 1. Fig. 5 is a similar view with the parts in an alternative position. Fig. 6 is an enlarged detail sectional view on line 6 6 of Fig. 5 of the electromagnetic controlling the latchbars. Fig. 7 is a perspective view of the key. Fig. S-is a crosssectional view on line 8 8 of 9 is a circuit-diagram, illustrating how the key' connected for shown-in Figs. 1 to 8-may be use with an operators cord-circuit to signal any one of the stations of a partysline.

The same characters ofreference are used to designate the same parts wherevezjthey are shown. 1 9-.

' The key illustrated comprises five actuating-shafts a a, mounted vertically to rock in hearings in the supporting-frame b,'each shaft carrying it the top above the face of the sup- I will describe my invention by reference mechanism "-95 Fig. 1 and Fig."

. I citin -frame a crankdever c which is ads a ed to be pulled by the finger of the operator to rock the corresponding shaft in either direction. '.hc shafts are mounted. at intervals in a line along the frai'nework, and each shaft is provided with two sets of individual switch-springs (Z d and e e, which are preferably mounted parallel to the shaft and on either side thereof, said springs being held in slots in insulating supporting-strips d (2", eX-

tending longitudinally along the bot-tom of the frame and forming a part thereof. Each shaft carries horizontallyprojecting armsf f forming a double rocking lever adapted to operate the springs dd and e e, respectively, associated with such shaft, according to the direction in which the shaft is rocked. Thus when the shaft is rocked in a clockwise direction the arm f serves to move the spring (1 into engagement with its anvil d, and when the shaft is rocked in a contra-clockwise direction the armf is adapted to close together contact-springs e e. '5. his construction -is especially adapted for advantageous use with ten party lines to signal the substations thereof and furnishes a very compact and efficient device which is exceedingly convenient for such use.

The switch-key above described is equipped with a blocking device adapted to be actuated in the movement of any one of the shafts a to prevent subsequent o;;=eration of the remaining shafts until the actual ed shaft re turned to its normal position, the blocking device also serving to lochthe actuatingsha'ft-in such a position for a predetermined period, when the shaft is returned to its n0r on and the blocking device counteruc :f. to restore the remaining shafts to operative condition. The mechanism which I prefer to use for accomplishing this work consists of two latch-bars g g, mounted to slide in bearings g g in the side of the framework, one bar lying on each side of the row of actuating-shaftso a. (See Figs. 4 and 5.) The bars 9 g are provided with series of teeth 9 g", respectively, and a cam h is car ried by each shaft, having ears h 72. respectively, adapted to engage the teeth g' g of the said latclnbars, according to the direction in which the shaft (2 is rocked, and so to move one or the other of the bars g g longitudinally. Either of the bars when thus advanced is adapted to engage the cams of the shafts in their normal positionsand act as a blockin device to prevent the operation thereof untfi the actuated shaft is returned to its normal position, the cam of the actuated shaft being held by said bar in its abnormal position. This 1 preferably accomplish by providing shoulders h t ton each cam adjacent to the bars 9 g, respectively, said siunilders when the cam is in its normal pos' ion lying to one side of the "O'tli'QlY. iins it 2 are cari can, one between each ear and eof, and the teeth of a bar when ried by e shoulder t sas es the same is advanced are adapted to engage a shoulder and pin of each cam in its normal position to lock the same against movement.

When ashaf't a is rocked in a contra-clockwise direction, as illustrated in Fig. 5, the ear h of the cam h of said shaft engages a to'oth g of the bar 9 and advances said bar longitudinally. The ear h and shoulder 7L3 now lie between the two teeth 9 of the bar g, and the cam will thus be held in its actuated position until the bar returns-to its normal position. The

' remaining shafts being in their normal posi tions, the teeth g adjacent to the shoulders 72, of the cams h, associated with such shafts,

are moved along the surface of the shoulders and into engagement with the pins it, so that the movement of the remaining cams in eitherdirection is prevented until the bar returns to its normal position. A magnet 6, carried by the supporting-frame, is provided with an armature i for locking either 'bar in the position to which it has been advanced by the movement of any one of said cams, said armature being preferably pivoted to the upper portion of the framework of the device. The armature may carry studs i vii-which normally rest opposite and adjacent to the ends of the bars 9 51 and each of said bars may have a recess i near its end adjacent to the studs i '2'? of the armature it, so that when either of the bars 9 g is moved by the rocking of any one of the shafts a a one of the studs i will enter the recess i of such bar and lock the same in its forward position, dependent upon the actuation of the mag'nethaspringi, associated with the armature i, serving to move the armature and force the stud into i said recess when the same registers therewith.

Thus in brief when any one of the shafts is rocked in either dlrection the cam 71 associated therewith engages one or the other of said latch-bars g g and advances the same longitudinally until such bar is locked by the armature i of the magnet "L. actuating-shaft is now held between two of the teeth of said bar and locked in its operative position, and the remaining teeth of the bar are in engagement with the cams of the remaining shafts, locking said shafts in their normal positions to prevent the actuation thereof until said bar has been released by the electromagnet t and the actuated shaft returned to its normal position.

Each of the bars 9 g is adapted when actuated by the rocking of any one of the shafts a. a to actuate sets of contact-springs, which may serve to interrupt the operators cordcircuit. Each bar may carry a piece 9 of insulating material arranged to actuate sets of switch-springs which may be mounted in slots in the supporting-strip in a manner similar to the mountin of the individual sets of switch-s rings d d ,and c e. A )air of springs f 7c (seeFig. 9) is adapted to be moved by the bar g, the spring it when so The cam of the SIG .moved breaking contact with its anvil k and I closing upon its front contact 70 while sprin'g 7c is moved into engagement with its anvil 70.

Similarly, the bar 9 is adapted-when ad-' vanced. to move a corresponding pair of springs Z Z. Springl when so moved is separated from its innercontact Z and moved into engagement with its front contact Z while spring Z closes upon its front contact A listening-key m ofWell-known'constrriction Ina be provided in association with the rin inge and ma be slu portedb the franeworli of the dei ice, as s hown.

Where party-line ringing-keys are enrploye'd, it often becomes necessary'to resignal a subscriber, and it is desirable to associate a target witheach of the-actuating-shafts of the key adapted to be displayed Whenever the shaft associated therewith is operated.

The target thus serves to identify t e shaft which was last operated and should remain.

displayed until another shaft. is operated, when such target will be withdrawn and the tar et associated with the newly-actuated sha t substitutedtherefor. If, therefore, the operator should have occasion to transmit a second signal, as in the case wherethe' called I subscriber does notrespond to the first signal,

- .she can tell by glancing at the ringing-key which of the shafts was last actuated'that is, which station was last signaled without ends of each two s iields are preferably necessitating any effort of memory on her part. i To accomplish this work in the he of my invention, I provide a series of shie'l s n n, Fig. 3,-slidably mounted in a bed-plate n immediately below the top plate n one series j of shields bein located on each side of the shaft is rocked, andseparate the same, so'

that one of the pair of targets associated with the shaft and normally concealed by the opposing ends of said shieldsmay be seen through an opening '0 in the top plate of the framework: A 'centrallyivoted 'rockin lever p is located at the en of the series 0 shields,with its two ends p" p abutting against the ends of the two series adapted to assist in the withdrawal or concealment of a diapla'yed 6o tar et when another shaft is operate I he operation of the signaling ap aratus above described may be :briefly out ined as follows: Assume the shaft a to be rocked ina contra-clockwise direction. -'Il;1e.wed e 0 will then be moved to separate two 0 the I prefer. to

.ite on the other, each shaft shields in theseries nto display the target 0 belongin to such shaft, which is normally. co'nceale by the said shields. next shaft'to be operated is rocked in the same direction the wedge associated there- Now if the with se aratingltwo other shields of the series n to isplay t e target of the'newlyactuated shaft will move the row of shields n'longitudinally in such a way as to unite the two shields previously separated, and so conceal the first-displayed target; but it" the; shaft subsequently actuated be rocked in aclockwise direction and separate two of the seg ments-n"-the lever will be rocked in a clock wisedirection, so that its'end p will move the shields of the series n longitudinally to close together the two shields first separated.

It will thus be seen that a target when displayed by the separation of-two of the shields of a serieswill remain displayed until some other-shaft a is rocked'in a'direction to sepa, rate two other shields of either series, when. the first-mentioned tar et will be concealed and a target .of the new y-actuated shaft disclosed.

' Referring now "to Fig. 9, Iwill describe a i s stem of circuits wherein the switch-key i' lustrated may be advantageously employed for code-signaling. The. metallic circuit telephone-line 1 2 is shown extending from ten substationsKfive bells on each side of the line)'t'o a spring-jackter'minal g at the central office, where connection may 'be made with the line by means of the operators plug and cord circuit. I have shown only a POT. -tion of the cord-circt'litassociated with'the calling-pin 'g, is concerned in the operation of t e ringing-key. The tip-strand 3 of the cord-circuit includes the contact spring is, adapted to be moved by bar g, and its back contact k while the rin -strand 4 of the plugrcircuit similarly inclu es the contact-spring Z, arranged to be moved. by bar 9,

and its back contact Z .The said springs 7c Z when moved are adapted to break connection with theirback contacts and to engage front contacts 76 lflrespectively, which are con nected in multiple branches of a conductor 5, leadi'n to the inner contacts (1 .e of switch- .springs which anvils are connected in parallel from said condirctonthe conddctorfi, including the armature r and its normally open contact of a relay r, hereinafter to be described.

The s rings (is of switches I to V are con- 'necte in multiple from conductors which lead to brushes bearing upon a continuouslyrotating commutator C adapted to supply current of distinctive characteristics to the switches I to V. The commutator C, which is shown developed into a plane, comprises two outer rings 8 8, each ring having a num, ber of commutator-se 'rnents s and 8 re spectiveiy, connected therewith; One ring 8 isconnected through the medium of a brush 6 of the five keys I II III IV V s? and conductor 6 with the free pole of a grounded genera tor G, while the ring 8 is connected to earth by way of a brush 3 and cond uctor 7. F i ve brushes t t t t t, bearing on the commutator, are adapted to pass over the generator-segments s as the commutator re volves and are connected by conductors 8 9 1O 11 12 with the springs d e of keys I to V, respectively; Thus in each revolution of the commutator the brush it would pass over one segment 8" and apply one short impulse of current from generator leading to switch I.'- Similarly, brush it in one revolution of the'commutator would engage two segments 8 and apply two short impulses of current to conductor 9, leading to switch II, &c. The commutator C would in practice be connected with the shaft of gen-' 7 mutator engages one grounded segment 8 Thus when either spring is or Z is closed upon its front contact and at the instant the brush 8 passes over thegrounded segment 5 a path for current from battery B will be completed through relay 1. The relay 1- has a third armature T, which is included, together with its normally open front contact, in a conductor 15, extending from the free pole of a grounded battery B through the winding of a releasemagnet 11, heretofore referred to, and connected with a brush 3 of the commutator, which is also adapted to engage one grounded segment 8' in each revolution of the commutator after the other brushes have all engaged their segments, and so to complete a circuit for the releaseanagnet t in case the contacts a r of relay 7 are closed.

The relay 1' is adapted when energized as just described to complete at its armature r and front contact'the continuity of conductor 5, leading from the switches to the cord-circuit to complete the ringing-circuit, to move the armature 1' into engagement with its front contact 7"", which is connected to earth by a conductor 16, and so complete a locking-circuit for the magnet '1 independent of the commutator, and finally in drawing up i ts armature 7" to transfer the control of the circuit of the magnet i to the commutator,whereby the apparatus may be restored to normal condition by the energization of release-magnet i when, after the propersiguals have been applied, the. brush 5 engages the grounded segment 1 The operation of thrs =;stcm is as follows: Assume that the operat orlias inserted the answering-plug of the cord-circuit in the an- G to conductor 8,-

swering-j ack of -the calling-line and has ascertained the particular subscriber of the part yline with whom communication is desired to be the one whose bell is connected from limb 1 of the line and designated as No. III, his code-signal thus being three rings. The operator after inserting the calling-plug 9 into the spring-jack qof the party-line rocks the shaft (1 of the switch-key No. III in a contraclockwise direction to close contact-spring c e. The bar 9 is by this operation advanced and locked by the armature of magnet i and in its movement severs the connection of spring with its anvil k and forces springs 7r 7c into engagement with contacts 7r lrr", respectively. The closure of spring Z? and its front contact 7c"- unites conductors 13 and 14, and as soon as the brush 8 passes over the grounded segment 8 the commutator rotatingin the direction of the arrow, a path for current from battery B is established by way of conductor 13, spring it and its front con tact k conductor 14, winding of relay 1', armature 7*, and back contact of said'relay, brush 8, segment 8 to earth. This circuit, which is of course but momentary, effects the energization of relay 1", which draws up all its armatures. The armature r in closing upon its front contact i completes a locking-circuit 13 1 1 16 for relay 1' independent of the commutator. 'Armature 1" completes the continuity of conductor 5, leading from the switch IIIto the contact is", which is now in engagement with the spring Ir, connected with the tip of the calling-plug, and armature r extends the circuit of conductor 15, including the release-magnett, to the brush 5. Immediately after the brush 8 leaves the segment 8 the brushes t to t will start their travel over the generator-segments s"; but the brush 6*, which in each revolution ofthe commutator engages three generator-segments s, will alone apply current to the line, since the key III, associated therewith, is the only key whose switch-springs are closed. The brush i in passing over the said segments applies three short impulses of current to conductor 10, leading to the now-closed switch-contacts e c of key III, which current passes over conductor 5, through the spring It and its front contact it", closed by bar 1, tipstrand 3, to the tip of the-plug, and thence over limb 1 to earth through the bells of the substations which are connected in grounded branches from said limb. As the comn utator continues to revolve and immediate y after the brushes t to z pass beyond the last i gmierator-segmcnt th'elirush's engages a grounded segment s and'icompl'ctes a circuit 1 for the release-magnet t, suigh cilicuit extending from battery Bj througl'i- 1h magnett, contacts I"- c winding of .r" ofrel: y 1', brush s.

. segment s. ring a. brush a, and conductor 7 to earth. The release-inagnetijuowbecomes energized and attracts its'arnuiti'irc i, thereby releasing the bar g, which in returning to its normal position breaks the connection of springs 1c 76 with their 'outer contact-anvils k is, respectively, and restores the. normal connection of spring k with its back contact k thereby restoring the continuity of the cord-circuit. The locking-circuit for there- 'lay r isxthus brokenat the spring is and con-,

tact 7c, and said magnet and its armatures are restored to their, normal conditi0n.- The bar gin returning to'its normal'p osition also releases the shaft a of key III, whereupon contact-spring e is separated from its anvil e,

In case thebell of the wanted subscriber is in a branch from the other side of the line the operator would rock the shaft a of the particular switch-key in a clockwise direction, thus moving the bar g in the same Way that bar 9 was moved, and the desired number of impulses would be applied to the limb 2 of,

the line in the same manner as above described, the apparatus being restored toits normal condition'when. the particular num-,

benof impulses are applied to the line and as soon as the brush 8 reaches the grounded segment It willthus be seen that to signal any subscriber it is simply necessary to set the required key and that. after the proper number of signals hasbeen transmitted over the line" the apparatus is all automatically restored to its normal condition. 7 v

It will'be apparent that my invention is capable of easy modification by thoseskilled in the art andthat various mechanical equivalents may be substituted for the specific mechanism set forth, and I do not desire to be understood as limiting my invention narrowly to the precise forms shown in the drawins; but

- claim- 1. In a switch-key the combination with a supporting-frame, of a plurality of setsof switch-springs mounted, thereon, an actuating-lever for each set of springs, a latch-bar 9 common to all of said actuatinglevers, said latch-bar being adapted to be moved in the ever in its actuated-position,,parts g? of said latch-bar adapted in the movement of said bar to be brought into'engagement with all of said levers remaining in their normal condition to prevent their movement, and a magnet adapted to control said latch-bar. i

2. In \a switch-key the combination with the supphrting-i'rame, of a plurality of sets of operption of any ofsaid levers and to hold said aving parts 9 prevent the movement thereof, an additional set of switch-springs arranged to be operated when said latch-bar is moved by any of said actuating-levers, and a magnet adapted to control the return of said latch-bar to its normal position. 3. In a party-line ringing-key, the combination with a supporting-frame, of a plural- 1ty of sets or switch-sprmgs mounted thereon, an actiiatingeleverfor each set of sprin s, a bar 9 common to all of said actuating evers and adapted to be moved in the movement of any of said levers, a latch. adapted to hold said bar in the position to which it has been moved, parts g carried by said bar adapted to enga e whichever of said levers has been operate and holdiit in its operated. position, and a magnet controlling said latch and adapted when energized to release the same to permit the retraction of said bar 4. A party-line ringing-key comprising a frame, sets 'of switch-springs supported on said frame, actuating-levers for said sets of switch-springs, a bar adapted to be moved in the, movement of any of said levers to hold said lever in the position to which it has been moved, a magnet, means controlled thereby adapted to hold said bar in its actuated position, and means for returning said bar to its normal position when released. l p

5. in a switch-key thecomblnation with a frame, of a plurality of sets of switch-springs mounted thereon, an actuating-leverfor each set of springs, a" latch-bar 9 common to all,

said aotua't ngdevers, said latch-bar being adapted to be-moved in the movement of any of'said levers'and to hold said lever inthe positionto whichit has been moved, and a magnet adapted to control said latch-bar.

6. The combination with a plurality of switch-keys, adapted for independent operation, of a blocking device adapted to prevent the operation of said keys, a magnet, and means controlled thereby adapted to hold said blocking device in its operative position.

7. A party-line ringing-key comprising a supporting-frame, a series of actuating-shafts mounted vertically to rock in bearings in said frame, a crank-arm carried by each shaft above the supporting-frame, two sets of switch-springs mounted vertically in association with each shaft, one-on either side* thereof, and arms carried .by each shaft adapted to operate said sets of springs independently of each other accordin to the direction in which said shaft is roc ed.

' 8. A party 'line ringing-key comprising a supporting frame, a series of actuatin -shafts mounted to rock in hearings in said frame, a crank arm carried byeach shaft above the supporting-frame, switch-springs for each shaft operated in the movement thereof, a latch-bar carried by the supporting-frame, a cam carried by each shaft in operative relation to said bar, each cam being adapted TIC) whereby a shaft IO crank-arm carried 5 by each shaft, each cam when its shaft is rocked to move said latchbar and be held thereby in its actuated. position, a magnet, and means controlled thereby, for locking said bar in its actuated position, when actuated is locked in such position until released by said magnet. 9. A party-line ringing-key comprising a supporting-frame, a series of actua-ting-shafts mounted to rock in hearings in said frame, a by each shaft above the supporting-frame, switch-springs for each shaft operated in the movement thereof, a latch-bar carried by the supporting-frame common to all of said shafts, a cam carried being adapted when the shaft is rocked to move said latch-bar and be held thereby in its actuated position, a magnet and means controlled thereby for locking said bar in its operative position, said bar when moved by a cam being brought 4 thereby for locking either bill their normal positions and revent actuation 'into engagement with the remaining came to lock the same in their normal positions and prevent actuation of the shafts associated therewith.

10. party-line ringing-key comprising, a support1ngframe,a series of actuating-shafts mounted vertically 'torock in hearings in. said frame, a horizontally-projecting crank-arm carried by each shaft above the supportingframe, sets of switch-springs associated with eachshaft on either side thereof adapted to be actuated by said shaft according to the direction in which the sameis rocked, a toothed latch-bar mountedupon either side of said series of shafts, a cam carried by each shaft adapted to engage a tooth of either bar to move the same, said cam when actuated being held between the teeth of the bar actuated thereby, a magnet and means controlled in its actuated position, and shoulders for said cam, one ad= scent to each of said here, the teeth of the ar which is moved being ade ted to engage the shoulders of those cams which remain in of the shafts associated Wit said came.

11. A party-line ringing-key comprising a supporting fram e, a series of actuating-shafts mounted vertically to rock in bearings in said 5 frame, a horizontally-projecting crank-arm carried by each shaft above the supportingframe, two sets of switch-s rings associated with each shaft, one on eit er side thereof, arms carried by each shaft adapted to move and springs accordingto the direction in which said shaft is rocked, a toothed bar carried on each side of said series of shafts, each bar'having a recess at one end thereof, a cam carried by each shaft adapted to engage a.

tooth of either bar to move the same according to the direction in which the shaft is rocked, and to be held by the teeth of said bar in its actuated position, contact-springs actuated'by each; barein its movement, a magnet, an armature therefor. studs'carried by said armature associated with such bar, each stud being adapted when its bar moved to enter the recess in sa id bar and lock the same in its advanced position, shoulders formed on each side of the cams. one adjacent to curb of said bars, pins carried by said cams, cithcr bar being adapted when operated to engage the shoulders and pins of the cams in their normal positions and prevent actuation of the shafts associated therewith.

12. A signal device for party-line ringinglioys cmnprising a series of shields movably mounted in a guideway underneath the face of the supportirig-frame, an arm carried by the actuatirig-sliai't of arch key, a wedge controlled by said arm adapted when said aotua t.- ing-shaftis rocked to 'scparai c a painof shields, a target concealed bythe adjoining ends of each two shields and adapted to be displayed when said shields are separated", the face of the supporting-plate having openings through which the targets may be visible, said target being concealed upon the actuation of another key due to the spreading of the shields by the wedge of such key.

13. A signal device for party-line ringingkeys comprising two series of shields movablv mounted in a guideway underneath the top plate of the supportingdrame, one series heing located upon each side of the actuatingshafts of the keys, targets of distinctive color concealed by the adjoining ends ofsaid shields, the face of the top plate of'the suprmrtingframe having openings above said targets, an arm carried by the actuating-shaft of each key, a double wedge controlled by said arm ada ted to separate a pair of adjoining shie (is of either series according to the direction in which said shaft is rocked, whereby the tar et associated with said pair of shields is disciiised, and means for concealing said target when another key is actuated.

14. A signal device for a party-line ringing key comprising two'series of shields slidably mounted in a guideway underneath the top plate of the supporting-frame on either side of the actuating-shafts of the keys, the ends of the shields of each series being beveled and adjoining one another, a target of listinctive color concealed by the adjoining ends of each two shields, the top plate of the supporting-frame having openings therein above the respective targets, an arm. carried by the actuating-shaft of each key, a double wedge controlled by said arm adapted to separate two shields of either series according to the direction in which the actuatin shaft is rocked, and a centrally-pivoted rocxing lever p, each end thereof engaging the'end of a series of. shields, tsaid lever being adapted when two shields of a series are separated to unite the separated shields of the other series.

15. Aparty line ringing-key comprising a series'of vertical rotatable shafts, individual switch-springs for each shaft operated in the movement thereof, a row of shields associated with said shafts, targets concealed by said shields, and means actuated in the rotation of any shaft adapted to separate said shields to display a target. 16. A switch-key com rising a supporting-- frame, an 'actuating-sha t mounted vertically to rock in bearings in said frame, a set of vertical switch-springs su ported by said frame switch-springs one on each side of the row of shafts, transverse slots in the sides of the insulating-base of the frame adapted to support said springs parallel to the shafts, each shaft having associated therewith a set of switch-springs of each row, a double rocking lever carried by each shaft adapted to engage one or the other of the switchsprings associated with said shaft, according to the direction of rotation of said shaft, and a double crank-arm carried by each shaft above the su porting-frame for operating said shaft.

n Witness whereof I hereunto subscribe my name this 6th day of June, A. D. 1904.

EDWARD B. CRAFT.

Witnesses:

EDWIN H. SMYTHE, E. F. BEAUBIEN. 

